Electric heating device



1952 F.- E. HASLEY ELECTRIC HEATING DEVICE Filed Dec. 2, 1950 FIG-l w E T L N S E A V H N F K m R E D E R F 2! FIG-4- ATTORNEY Patented Nov. 4, 1952 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to electric heating devices, and the principal object of my invention is to provide electric heating devices comprising improved terminal provisions.

In the drawing accompanying this specification and forming a part of this application I have shown for purposes of illustration one form which my invention may assume, and in these drawings:

Figure l is a side elevation of a heating device embodying the illustrated form of my invention;

Figure 2 is a top view of the heating device of Figure 1; 7

Figure 3 is an enlarged top View of the overlying member of the device of Figures 1 and 2; and

Figure 4 is an enlarged partial section on the line 4--4 of Figure 2.

The heating device shown in the drawings is of the type commonly used for heating liquids, and comprises a heating element In including a resistor H designed for the passage of an electric current and the consequent generation of the desired heat, terminal pins [2 to which the ends of the resistor H are suitably secured, a sheath l3 suitable to the temperatures to be experienced and commonly of metal, and refractory material I4 embedding the resistor I and the inner ends of the pins l2 and serving both to electrically insulate the resistor and the pins and also to conduct the heat from the resistor to the sheath.

In the present embodiment the element In is bent upon itself, providing a body portion I5 suitable to be inserted into the liquid to be heated, as through an opening in the wall of the tank or other vessel in which the liquid is contained, and in furtherance of this arrangement the two substantially parallel end portions |6 are pressed or otherwise secured fluid-tight in openings I! in a plate l8 containing further openings H] by means of which the plate |8 may be bolted or otherwise suitably secured to the wall of the tank or other vessel marginally of the opening through which the body portion l5 has been inserted.

According to the present embodiment the refractory material I4 is not extended to the ends of the sheath, or is routed out short of the ends of the sheath, and the heater is provided with closure means including bodies of electrical insulating material applied about the terminal pins |2 and an overlying member 2| provided with traversing apertures 22 through which the terminal pins |2 extend, the member 2| being provided also with inner-face recesses 23 encompassing the inner ends of the apertures 22, and

being pressed into position causing the bodies of material 20 to fill the respective spaces within the ends of the sheath l3 and the inner-face recesses 23 in the member 2| and extend outwardly between the inner face of the member 2| and the outer face of the plate l8, as indicated respectively at 26a, 20b, and 200, thus providing at each terminal a continuous electrical insulation between the terminal pin I2 and the sheath !3 and plate I8, independent of the overlying member 2|, and also affording a cushion operat-- ing to avoid breakage of the member 2| in the construction of the heater,

For this method of assembly the material 20 necessarily must then be in a plastic or flowable condition, and preferably the material 20 also is or becomes elastic and adhered to the various surfaces with which it is in contact, particularly the exterior of the terminal pins l2 and the interiors of the end portions of the sheath I3, and preferably also the end surfaces of the sheath IS, the outer surface of the plate l8, and the inner surface of the overlying member 2|, including within the member recesses 23.

At the present time I consider most satisf'ac tory for the material 20, a suitable uncured and slow curing substantially inorganic rubber, preferably having admixed up to twice its weight or more of a substance suitable as an aggregate, the proportions depending on such factors as the specific ingredients, the specific application, the viscosity of the rubber, and the particle size of the aggregate, and a particular example being approximately equal parts of the silicone rubber known commercially as Silastic 120, and zircon ground to as fine as mesh or finer.

Under some circumstances the adhesions of the material 20 may be sufiicient to hold the overlying member 2| in position, but in the present embodiment the member 2| is further provided with outer-face recesses 24 laterally adjoining and open to the respective apertures 22, and suitably secured to the terminal pins l2, as by welding at 25, are connection terminals 26 each comprising a strip 21 bent intermediately at substantially a right angle, provided in its outer section 28 with a screw-threaded aperture 29 receiving a binding screw 30 adapted for the attachment of a supply conductor, and each having the inner end 3| of its inner section 32 seated in the respective recess 24 of the over lying member 2| and thereby operating to maintain the member 2| in assembled position.

With the described construction, the further interrelation between the outer portions 20b of 3 the bodies 20 and the overlying member recesses 23 operates to retain the member 2i also against movement parallel to the plate I8, and the interrelation between the terminal pins l2 and connection terminal inner ends 3! and the respective apertures 22 and recesses 24 operates to hold the connection terminals 26 and terminal pins I2 against rotation upon application or removal of the supply conductors.

From the foregoing those skilled in the art will appreciate that the described embodiment accomplishes at least the principal object of my invention. However, obviously various changes may be made, and therefore it is to be understood that the present disclosure is illustrative only, and that my invention is not to be regarded as limited thereto, but to be defined by the claims herebelow set forth.

Wherefore I claim:

1. An electric heating device comprising resistor means, tubular sheath means in general enclosing said resistor means, said sheath means having an open end and said resistor means including a terminal member extending through the opening in said end, flange means secured to said sheath means adjacent said end, closure means for said opening, permitting connection to said terminal member and electrically insulating said terminal member from said sheath means, including a member overlying said opening and at least the adjacent surface of said flange means and provided with an aperture through which said terminal member extends, and a mass of matter comprising essentially an uncured rubberlike material which is initially in a plastic or fiowable condition and is or becomes elastic on curing, adhered to said terminal member and said sheath means and interposed between said overlying member and the end surface of said sheath means and at least the adjacent surface of said flange means, said overlying member being constructed and arranged to retain said matter in location, and means constructed and arranged to hold said overlying member in position.

2. An electric heating device comprising resistor means, tubular sheath means in general enclosing said resistor means and provided in each end with an opening, said device being so constructed and arranged that said openings are adjacent and open in approximately the same direction and said resistor means including terminal members extending through said openings, a flange secured to said sheath means adjacent said ends, closure means for said opening, permitting connection to said terminal members and electrically insulating said terminal members from said sheath means, including a member overlying said openings and at least the adjacent portions of said flange and provided with apertures through which said terminal members respectively extend, and matter comprising essentially an uncured rubber-like material which is initially in a plastic or fiowable condition and which is or becomes elastic on curing, adhered to said terminal members and said sheath means and interposed between said overlying member and the end surfaces of said sheath means and at least the adjacent portions of said flange, said overlying member being constructed and ar- 4 ranged to retain said matter in location, and means constructed and arranged to hold said overlying member in position.

3. An electric heating device comprising resistor means, tubular sheath means in general enclosing said resistor means and provided in each end with an opening, said device being so constructed and arranged that said openings are adjacent and open in approximately the same direction and said resistor means including terminal members extending through said openings, a flange secured to said sheath means adjacent said ends, closure means for said openings, permitting connection to said terminal members and electrically insulating said terminal members from said sheath means, including a member overlying said openings and at least the adjacent portions of said flange and provided with apertures through which said terminal members respectively extend, and matter comprising essentially an uncured rubber-like material which is initially in a plastic or fiowable condition and is or becomes elastic on curing, adhered to said terminal members and said sheath means and interposed between said overlying member and the end surfaces of said sheath means and at least the adjacent portions of said flange, said overlying member being constructed and arranged to retain said matter in location, and connection means secured respectively to said terminal members, coacting with said overlying member to hold said overlying member in position and to be held by said overlying member against rotation.

4. A sealing closure for an electric heating device having resistor means including a terminal and sheath means generally enclosing said resistor means, and provided with a tubular portion defining an opening through which said terminal extends, said closure comprising a mass of uncured rubber-like material which is initially in a plastic or flowable condition and is or becomes elastic on curing, and adhered to the surfaces with which it is in contact, disposed Within said opening and in sealing engagement with the adjacent inner wall surface of said tubular portion and the adjacent surface of said terminal, said material extending outwardly of said opening, and a member overlying said opening and having a recess providing a surface encompassing said tubular portion and shaping the rubber-like material in its plastic or flowable state and prior to curing thereof about and against the terminal end and the adjacent outer Wall surface of said tubular portion, said overlying member being constructed and arranged to retain said rubberlike material in location, and means constructed and arranged to hold said overlying member in position.

FREDERICK E. HASLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,916,80e McNab July 4, 1933 2,471,609 Charbonneau May 31, 1949 2,486,675 Pokras Nov. 1, 1949 

